Pump



April 1940- D. B. BAKER 2,197,288

I P UMP Filed May 27, 1937 3 Sheets-Sheet '1 April 16, 1940. B BAKER 2,197,288

PUMP

Filed May 27,- 1957 3 Sheets-Sheet 2 Patented Apr. 16, 1940 David B. Baker,

' tion of New Jersey PUMP Riverside, Ill., assignor to '3 International Harvester Company,

a corpora- Application May 27, 1937-, Serial No. 144,990

19 Claims.

This invention relates to improvements in gas moving devices. More particularly it relates to means for mounting an impeller *o-r'rotor in a device particularly adapted for air compressors or vacuumpumps. v

An example of such" a device is found 'inthe Nash Patent 1,091,529, March v31, 1914, which shows animpeller typeofpump in which the spaces between the rotor or impeller'blades form buckets. The impeller i's-'-'usually driven by an electric motor, beingpreferably mounted on the motor shaft for rotation therewith. By rotation of the impeller the liquid is thrown. outwardly therefrom: into an enlarged portion of the: impeller casing, thereby producing'a suction. Due to the shape of the around a smooth wall thereof and is again picked up by the impeller blades, thereby filling the buckets formed by the blades and discharging the gas therein.-This type of pump has been found to have aparticular utility in combination with apparatus requiring delivery of air fora predetermined length of time, as disclosed and claimed in assignees Patents Nos. 2,077,871, April 20; 1937, and 2,124,185, July 19,1938, relating to Milk refrigerating cabinets. v

As disclosed in said patents, however, the rotor or impeller is rigidly secured to the motor shaft and no provision is made in the drive connection between the shaft and theimpeller to allow relative axial movement, however slight. It'is found that this slight relative movement is desirable,

in as much as the bearings in few motors permit perfect alignment and axial-positioning of. the motor shaft with respect tomechanism driven thereby, unless said motors are provided with high grade ball bearings: In manufacturing experience with pumps of thetypehereinbefore referred to, it wasfound difficult to manufacture the pump in the form which the rotor -or impeller was rigidly secured to the motor shaft.

For instance, the "impeller, whichis rigidly se cured to the motor shaft, must operate within the impeller chamber and very close to the'axia-lly cposite walls thereof without touching. In specific instances; this clearance should be generally about .003 inch to .005 inch. If the impeller and the rear Wall of the impeller chamber touch, when made of metal, two surfaces results, which increases the run ni-ng clearance therebetween. v clearance between the impeller and the wall is excessive, then a considerable-amount of air leakage occurs, detracting from the efliciency of the pump. In addition, the motor shaft on which casing the liquid" moves" a roughening of the If the running' the impeller is secured must be held carefully by specialbearings so that no-appreciable amount of end motion can-take place. l

It is, therefore, desirable to simplify manufac, turing of the pump, inasmuch as simplification 5 provides an improved pump and reduces manufacturing costs thereof. In the present improved a construction of the pump, the impeller is, mounted on the motor shaft in amanner permitting relativeaxial movementand means are carriedv by p the shaft for. drivingthe impeller.- At the same: time, itis found desirable to employ an impeller made of a non-metallic material, such as hardened fibrous material,-. afphenolicv condensation product, or the like, that is very resistant to water absorption. Bymakin'g the impeller. of this material, the complications resulting from rubbing between the impeller and the chamber wall are eliminated and thev impeller is free to motor shaft move axially with respect to the. within the. impeller chamber. I

'The principal objectof. the. invention, therefore, isthe mounting o fthe impeller on the'motor she-ft in a mannerperinittifig relative axial movement therebetween. I I An important object of the invention is-to. providean impeller composed of nonemetallicg'material, as hereinbefore. mentioned.

Another important object-of thei-nvention is to provide the impeller with a metal bushing in its-hub to-provide a bearing surface.

Another object of the invention is to provide means on. the motor shaft fordriving theimpeller. v I

Stillanother object is to make. the above provision in such a manner as will permit easy removal and installation of the impeller and the component parts of the means forming the drive connection.

Still another object is generally to provide 40 means for allowing the impeller to float on the motor shaft within the limits'of the impeller chamberfi l H Specifically, an important object of the invention' is to provide a member rigidly secured to the motor shaft for rotation therewith and on which is carried, for axial-movement with respect thereto, the impeller; said impeller being driven by a drive'member associated With-the sleeve and the shaft for rotation therewith.

Briefly and specifically, th'esefand other important objects are'attained in a pump of the type hereinbefore referred to by the provision of a drive sleevej secured to themotor shaft, a

rotor or impeller-carried thereon, for axial move- -ATENT;io F-lc rsv The conduit plate ment with respect thereto and a drving connection between the shaft and the impeller for rotating the impeller with the shaft.

A further understanding of the objects and desirable features of the invention may be had from the following description taken in connection with the illustrations of a preferred construction as shown in the accompanying sheets of drawings, in which: I

Figure 1 is an end elevation of the assembled p p;

Figure 2 is a substantially vertical section taken on the line 2-2 of Figure 1; 1

Figure 3 is an elevation plate;

Figure 4 is an the conduit plate;

Figure 5 is an elevation of the open side of the f the outer conduit main casing with the impeller shown in position and with a liquid sealing medium indicated by broken line; c

Figure 6 is an elevation of the closed side of the impeller showing the driving connection with the shaft;

Figures '7 and 8 are respective side and end elevations of theimpeller drive sleeve showing the means thereon for engaging the impeller driving member; and,

Figure 9 is a detailed end view of the drive member. I

The pump illustrated herein consists essen-- tially of four principal elements. The main casing in is secured by brackets H to an electric motor l2, a portion of which is shown in Figures 1 and 2. The main casing Ill is provided with an impeller chamber I 3, being closed at one side by theconduit plate M and a gasket I4 and closed at the axially opposite side by a rear wall lllaIformed as an integral part of the casing [0. l4 and a cover plate Ila are held in place on the main. casing It by a plurality of cap screws." An impeller or rotor l5 is driven by the motor shaft l6 and is rotatably mounted in the main casing in the impeller chamber l3. With these main elements being generally described, their relation will be described in detail.

The impeller. [5- is preferably composed of a non-metallic material, as hereinbefore referred to, and is provided with a hub l1 into the central bore of which is fitted, for rotation therewith, a metal bushing l8. When the impeller is molded as a phenolic condensation product, the metal bushing i8 is preferably molded directly therein. This metal bushing 18 provides a bearing for the impeller on a drive sleeve l9 which is keyed by a key' [9a onto an extension of the motor shaft IS. The drive sleeve I9 is cut out at one end to provide a pair of diametrically opposed lugs 20 which form means for engaging corresponding openings formed in an impeller drive member or means 2| carried by the shaft H3. The openings in the member 2| for mounting the same onthe shaft l6 and for engagement with the drive sleeve 19 are best shown in Figures 6 and 9. In this manner, it may be said that the motor shaft l'B carries the drive member 2| for rotation therewith. The drive member 2| abuts a shoulder formed on the shaft l6 and is held against axial displacement by a cap screw 22 threaded into the free end of the shaft.

The above described construction is preferred as a matter of simplicity in manufacturing and also to'allow for the utilization in former constructions of' the improved impeller construcelevation of front side of struction is thereby formed which one of a plurality of angularly spaced web portions formed by axially extending, arcuate re cesses disposed about the hub I! of the impeller 15, as best shown in Figure 6. The webs and recesses are formed generally for the purpose of decreasing the weight of the impeller and at the same time to reenforce and strengthen the central portion thereof. With these provisions made, a simple and efiicient driving connection may be effected between the impeller and the drive member 2|, wherein the driving lug Zla axially entersan' aforesaid recess and abuts a web in driving. relation.

Generally, the arcuate webs, as shown in Figure 6 is considerably extensive, and while more relative angular movement is permitted than is needed between the impeller and the driveelement, it does not detract from the operation of the pumpf and at the same time the result serves as a feature of the invention. In short, since the aforesaid recesses and webs are provided in the impeller for other reasons, it is not undesirable to take advantage of the same to establish part of the means for driving the impeller. In any event, in order to simplify manufacture of the pump, some means of engagement between the drive member and the impeller would have to be provided, and in order to prevent binding between these two parts, such means would almost of necessity have to permit relative angular movement between the two, unless expensive finishing processes be resorted to. I

Adjacent the rear wall Illa of the pump casing Hi, the motor shaft i6 is provided with appropriate means 23 for throwing liquid outwardly during rotation of the impeller, thereby preventing liquid from reaching the bearings of the motor. This means 23 is positioned between the drive member 2| and a second shoulder or flange formed on the shaft It.

From the outer end of the hub l1 of the impeller IS, a radial flange 24 extends outwardly to connect the hub with a cylindrical flange 25 which forms the base for spirally arranged, circumferentially spaced impeller blades 26. At

the outer ends, the spaces between the impeller blades, which may be termed as pockets, are open on the radial face of the impeller. At the other end, the spaces are sealed by a radial flange 21. At its periphery, said flange is provided with an annular lip 28, which is utilized, as will be hereinafter described, to reduce the amount of liquid which by-passes the impeller on the inner face.

The main casing I0 is provided, as previously stated, with an impeller chamber l3. Said chamber is substantially cylindrical at each end with the two ends spaced apart and joined by flattened side walls. A conmight be termed as somewhat elliptical in shape and having a smooth inner contour, around which fluid may readily flow with a minimum of resistance. As best shown in Figure 5, the impeller chamber is arranged with its larger dimension at an angle distance between the enemas is tightly fitted. Said sleeve carries a radial flange which. terminates closely adjacent the sealing means 23. Any liquid which. escapes around-the impeller must passbetween. the edge of said flange and said means. The-liquid then is thrown outwardly by the means into the cy-f lindrical recess 30. A drain conduit 32 communicates with the cylindrical recess through an opening formed in the sleeve 3|. Said drain conduit extends downwardly and across the bot tom of the casing communicating with the air inlet means to the'casing, as will be hereinafter.

described.

It will be noted that the inner wall Illa of the casing I0 is provided with. a shoulder 33 within the impeller chamber l3. This shoulder. 33 lies closely adjacent the impeller l5'and over-hangs the periphery of the flange 21 thereon. Adjacent the shoulder 33 and at right angles thereto, the inner wall 18a. is provided with an. annular machined or finished surface lb. The impeller ii, at its inner end, is also provided with an annular finished surface l5a which cooperates with the annular surface lilb to prevent leakage of liquid or air from the impeller chamber l3. Because of the composition of the impeller l5 of nonmetallic material, as hereinbefore described, the liquid provides ample lubrication tocompensate for contact of the surfaces l5a and lllb while the impeller 5 is floating axially on the shaft it within the impeller chamber l3. This construction is made possible only by provision of the drive connection embodied in. the present invention, and a minimum amount of liquid escapes past the impeller without an actual constantly contacting seal. The small amount oi -liquid which does escape is drawn backinto thesystem through the drain 32. An important advantage of this. construction lies in the fact. that the impeller is free to float axially without damage to surfaces lb and i511, and therefore, no special provision for lubrication is required. I

There is also an advantage in the fact that when the impeller is running idle, that is without the supply of liquid, there is no bearing friction present and no resulting load therefrom on the motor because of the aforesaid relative axial movement.

The conduit plate [4, as shown in Figures 3 and 4, is provided with an inlet conduit 34', which terminates at its lower end in. a tubular extension 35 on which a flexible hose may be fitted. Said inlet conduit communicates with two branch inlet conduits 36 extending. through the plate. The outlet ends of said conduits are diametrically opposite each other. The conduits terminate at the open ends of the pockets formed by the impeller blades adjacent the bottom walls thereof, which are formed by the flange 25. As the liquid is thrown from the pockets air is drawn in through the inlet conduits. 36.

It will be noted in Figure 2 that at its. point of communication with the conduit-plate M, the extension 35 is. flattened and restricted in -cross section. A nozzle efiect. is thereby obtainedwith:

the: casing I0 is provided with a cylindrical recess 30 in which a sealingsleeve3l therefrom- Mixture of air and her 44. ,l It so happens thatin the pump disclosed'here- Liquid from the which communicates with the an. expanding stream of air. drain conduit 32,

inlet' conduit at this point, is entrained and car'- ried with the inlet air back into the impeller chamber.

A small drain opening 32 is formed in the conduit plate M. munication between the impeller chamber I1 and the inlet conduit 34 and provides a drain for the chamber when the pump is not in operation.

For. supplying liquid to the pump to initiate operation, a filling conduit 3'! connecting with the lower branch inlet conduit 35 extends up wardlyxthrough the conduit plate and communicates with a filling casing I0. Said conduit communicates with an enlarged filler neck 39, covered by a cap Ml. Said cap :closely fits over the top of the fillingfneclr and'is pivoted forswinging upwardly when water .is supplied. a

It will be understood that suction produced by the impeller inthe inlet conduits will act to maintain the cover'dii in a closed position. Such i The outlet openings M communicate with outlet conduits 42. leading upwardly and merging conduit 38 formed inthe c Said opening formsya com air as maybe drawn in around the filler cap does into an outlet 'conduit43, which discharges at a high point in the casing into a liquid chamber 44 formed in theiupper portion of the casing above the impeller chamber l3. Because of the highspeed of: an electric motor, considerable agitation isproduced'in the impeller chamber with the result that a considerable percentage of the liquid therein escapes with the air discharged Water. is dischargedinto the liquid chamber with a substantial percentage of the water separating therefrom- A certain amount of the waterentraine'd as afine mistby the air is discharged from the upper end of the water chamber through an opening communicating with a discharge conduit 35 formed in the conduit plate M. Said conduit, as best shown in Figure '3, extends to the lowerend of the cover plate communicating with an outlet extension 46.

v It will be understood that when the device, as described, is put into operation, liquid poured into the filler neck 39 passes into the impeller chamber, filling said chamber completely except for the amount displaced by the impeller blades at each end of the chamber. Thel-iquid supplied inexcess of this amount is forced by th'e impeller through the outlet conduits into the waterchainin, the balance of pressures is such that the impeller is forced toward the wall Illa of the easing It! with a pressure of approximately one to two pounds totahto be specific, when water is by means of a conduit 41 formed in the The impeller I5 is so constructed and -positioned that all of the liquid therein drains to the which is in communication conduit plate with the inlet conduit 34. To regulate the flow of water through said conduit, a bore 48 extending through the cover plate and into the conduit plate passes through a restricted portion of the conduit 41. A metering pin 49 is fitted in said bore, being secured therein by a cap-screw 50 on the cover plate Ida. Said metering pin is provided with a transverse metering opening 5! which determines the rate of liquid flow passing through the conduit 41 into the inlet 34.

In the operation of the device, water from the chamber 44 is continuously returned to the impeller chamber, thereby replenishing. a substantial portion of the amount carried through the outlet conduits. However, as an appreciable amount is carried over through the discharge conduits, the water in the chamber 44 is gradually depleted during operation. When the entire supply has been depleted, the amount in the impeller chamber is soon reduced until it is no longer sufficient to maintain a seal over the impeller blades and to provide for displacing air in the pockets formed by said blades. The suction is then broken at the inlet side of the device with the result that the remaining liquid drains downwardly through the inlet extension 35. By such a construction, the operation of which has been described in connection with the description, a pump is provided which forces air for a predetermined length of time. After the seal has been broken, air is no longer forced through the discharge conduit. A partcular advantage of this pump for an operation of this type is that, when effective operation of the pump ceases, there is no friction or wear. The motor, which may be operating other parts, such as the compressor of a cooling system, may continue to run without any appreciable load caused by the impeller, which is merely fanning the air around the impeller chamber, and with no resistance due to friction of pump bearings. Also, while the motor is operating other parts, the motor shaft may have slight axial movement with respect to the impeller, because of the improved drive connection disclosed herein.

Thus it will be apparent from the above description, that the assembly of the unit is greatly simplified, and in manufacturing it is necessary only to see that certain clearances exist between the opposite sides of the impeller and the impeller chamber.

It will be understood that applicant has shown only a preferred embodiment of his improvements in the particular type of air moving devicedisclosed, and that he claims as his invention all modifications falling within the scope of the appended claims.

What is claimed is:

l. In an air pump including a casing formed with an impeller chamber and a shaft extending thereinto, the combination with the shaft of an impeller carried thereby for relative axial movement, and a driving connection between the shaft and the impeller permitting slight relative angular movement therebetween.

2. In an air pump including a casing formed with an impeller chamber and a shaft extending thereinto, the combination with the shaft of a sleeve carried thereby for rotation therewith, an impeller carried on said sleeve for free relalow point at one side,

aromas tive axial movement; and a: driving connection between the sleeve and the impeller. -3."In an air pump including a casing formed 'with an impeller chamber and a shaft extending thereinto, the combination with the shaft of a sleeve carried thereby for rotation therewith, an impeller carried on'said sleeve for free relative axial movement, and means carried by the sleeve for rotation therewith and engaging the impeller for rotating the impeller with the shaft.

4. In an air pump including a casing formed with an impeller chamber and a shaft extending thereinto, the combination with the shaft of a sleeve carried thereby for rotation therewith, an impeller carried on said sleeve forfree relative axial movement, and means carried by the shaft and engaging the sleeve and the impeller for rotating the impeller with the shaft. 5? In an air pump including a casing formed with an impeller chamber and'a shaft extending thereinto,-the combination with the shaft of a sleeve'carried thereby for rotation therewith, an impeller carried on said sleeve for free relative axial movement, a drive member associated with the shaft and the sleeve for rotation therewith and engaging the impeller.

6. In an air pump including a casing formed with an impeller chamber and a shaft extending thereinto, the combination with the shaft of a sleeve carried thereby for rotation therewith, an

impeller carried on said sleeve for free relative axial movement, a drive member carried by the shaft and engaging the impeller, and means on the sleeve engaging the drive member for rotation therewith. r

'7. In an air pump including a casing formed with an impeller chamber and a shaft extending thereinto, the combination with the shaft of a sleeve carried by the shaft for rotation therewith, an impeller carried. by the sleeve for free relative axial movement, and means associated with the shaft'and the impeller and engaged by the sleeve for rotation therewith.

8. In an air pump including a casing formed with an impeller chamber and a shaft extending thereinto, the combination with the shaft of an impeller carried thereby for relative axial movement for cooperating with a wall of the cham ber to form an air seal therewith, said impeller being composed of non-metallic material and having a central metal bushing fitted therein to provide a bearing between the impeller and the shaft, and a driving connection between the impeller and the shaft permitting slight relative angular movement therebetween.

9. In an air pump including a casing formed with an impeller chamber and a shaft extending thereinto, the combination with the shaft of an impeller carried thereby, said impeller being composed of a non-metallic material and freely movable axially on the shaft to form an air seal with a wall of the impeller chamber, and a drive connection between the shaft and the impeller.

10. In an air pump including a casing formed with an impeller chamber and a shaft extending thereinto, the combination with the shaft of a sleeve carried by the shaft for rotation therewith, an impeller carried on the sleeve for axial movement therebetween to form an air seal with a wall of the chamber, a drive member carried on the shaft and engaging the impeller, and a drivinglug on the sleeve engaging said drive member to rotate the impeller with the shaft.

-. 11. In an air pump including a casing formed with an impeller chamber with an impeller chamber and ashaft-extending thereinto, the combination with the shaft of a sleeve carried by the shaft for rotation therewith, an impeller carried on the sleeve for axial movement therebetween to form an air seal with a wall of the chamber, and a radial arm carried by the sleeve for rotation therewith, said arm engaging the impeller for the shaft.

12. In an air pump including a casing formed and a shaft extending thereinto, the combination impeller carried on the sleeve for relative axial movement therebetween, and a radial arm, carried by the shaft for rotation therewith and engaging the impeller for rotation thereof with the shaft.

13. man air pump including a casing formed with an impeller chamber and a shaft'extending thereinto, the combination with the shaft of a sleeve carried thereby for rotation therewith, an impeller carried on the sleeve for axial movement with respect thereto, said sleeve being composed of non-metallic material and including a mctal-- lic bushing fitted at the center thereof to provide means for mounting the impeller on the sleeve, and a driving member carried by the shaft and engaging the sleeve for rotation therewith, said driving member including a portion engaging the impeller.

14. In an air pump including a casing formed with an impeller chamber and a shaft extending thereinto, the combination. with the'shaft of an impeller disposed concentric with theshaft, a sleeve carried by the shaft for rotation therewith and permitting free relative axial movement between the impeller and the member carried by the sleeve for rotation therewith and engaging the impeller.

15. In an air pump including a casing formed with an impeller chamber and a shaft extending thereinto, the combination with the shaft .of an 7 rotation thereof with with the shaft of an with an impeller chamber thereinto, the combination Jimpeller disposed concentric with the shaft for shaft, and a drive and permitting relative axial movement between impeller disposed concentric the; shaft, sleeve carried by the shaftffor rotation therewith the impeller and the shaft, and ,a drive member carried by the shaft and engaging the sleeve and the impeller for rotation therewith.

16. In an air pump including a casing formed with an impeller chamber and a shaft extending thereinto, the combination with the shaft of an impeller disposed concentric with the shaft, a sleeve carried by the shaft for rotation therewith and permitting relative axial movement between the impeller and the shaft, and a drive member carried by the shaft for rotation therewith and engaging the impeller andpermitting slight relative angularv movement between theimpeller and the shaft.

17. In an air pump including a casing formed with an impeller chamber and ashaft extending thereinto, the combination with the shaft of a sleeve carried thereby, the sleeve in a manner an impeller carried on permitting free relative movement between the impeller and the shaft,

and a driving connection between the shaft and the impeller.

18. In an air pump including a casing formed with an impeller chamber and a shaft extending thereinto, the combination with the shaft respect thereto.

19. In an air pump including a casing formed and a shaft extending with the shaft of an DAVID B. BAKER.

of a sleeve carried thereby for rotation therewith, .an impeller carried onthe sleeve for rotation 1 therewith and for ire movement axially with 

